As a company with more than 20 years of R&D capabilities in inverters and household energy storage and power management, RCT Power is one of the few household energy storage solution providers in the world. It develops, manufactures, sells and services inverters, energy storage battery modules and power management modules. The teams at RCT Power in China and Germany have jointly developed household energy storage products for the European market, which have a high reputation in the European market. In an energy efficiency test conducted at the University of Applied Sciences (HTW) in Berlin in June 2021, RCT Power ranked first in the industry. RCT Power has been deeply engaged in the energy storage business, and its products have been sold to more than a dozen countries and regions such as Europe and the United States. By the end of 2021, the cumulative shipment was 2.0 GWh.
In 2021 to keep up with the growth in deployment of RTC Power systems, we decided to upgrade our software solution – RTC Power Cloud. The goal was to make it connectable to photovoltaic inverters and energy storage and power management systems. The systems deployed at consumer sites are connected to the local power company to allow plug and play, remote scheduling and data monitoring. RTC Power Cloud abandoned the old technical architecture and decided to adopt the most cutting-edge technologies. Specifically, the RCT Power Cloud need an extremely high-performance time series database (TSDB) engine to store and process time series data. We looked at several solutions such as TDengine, Apache IoTDB, and Alibaba Cloud Time Series Database. After detailed comparison and consideration, we made the final decision – TDengine. The main reasons for choosing TDengine are as follows:
- TDengine is an efficient platform for storing, querying and analyzing time series Big Data because it is designed from scratch and optimized for IoT. With native cluster functionality which is open source, it is highly suitable for RCT Power’s high growth trajectory.
- TDengine supports SQL and so it is easy to learn, and easy for current technical teams to get started with.
- The full stack, “All-in-One” architecture reduces complexity and makes operation and maintenance simpler and reduces TCO.
Given this, we also decided to buy the Enterprise Edition support for our deployment of TDengine.
At present, our residential energy storage system has been launched on Amazon cloud, and the industrial and commercial energy storage system is still under development.
Prior to launching the RCT Power Cloud, our devices could only be directly connected through the local area network, and could not save all historical operating data. When there were disruptions, due to lack of real-time monitoring, at most it was possible to see a little operating data of the minutes before and after the disruption. Lack of real-time monitoring was also a big problem for our after-sales service. With our new RCT Power Cloud platform we have real-time, multi-parameter device tracking through the data written into TDengine. For example, if the system sees that the temperature of the user’s photovoltaic panel is above the threshold, the system can proactively send the customer an early warning SMS or email. Additionally in the past, if the customer’s equipment was behaving abnormally it was necessary to send maintenance personnel to the site for maintenance. With the new system, customer service can directly troubleshoot customer equipment through the background operation and maintenance system. For simple issues, the equipment can be restored to a normal state by issuing remote commands, which not only saves the customer time and money but also reduces RCT Power’s after-sales service costs.
TDengine has been officially running in our production environment for about half a year, but the amount of data is not very large. However as we upgrade our European equipment and deploy more equipment in the global market, we firmly believe that TDengine provides a solid foundation for our increasing high-performance requirements. This is one of the reasons why we bought the Enterprise Edition. Currently we have TDengine 2.0.20.4, and it is deployed on a single machine which can handle the current load with ease thanks to the efficiency of TDengine. Data is temporarily backed up through cloud services. As the scale of the business expands we will add a multi-copy cluster.
In daily use, many common functions can be solved with a single SQL statement, which is simple and efficient. Let’s look at a few typical applications.
1. The last record of daily indicator data, such as daily power generation:
select last(value) as value from tsdb.inverter where devid = #{deviceId} and pointid = #{pointId} INTERVAL(1d)
2. Retrieve the subtable through the supertable, then use downsampling to query the daily income of the device, and push the data to the application side for display:
select sum(value)/1000 as value from tsdb.profit where devid = #{devid} INTERVAL(1d)
3. The 5-minute average of the metrics is obtained by using a downsampling query on the supertable:
select avg(value) as value from tsdb.inverter where devid = #{deviceId} and pointid = #{pointId} INTERVAL(5m)
There are other commonly used queries, which basically return results in milliseconds, so I won’t go into details here.
TDengine is an excellent time series database product and it coincides well with RCT Power’s global business and I look forward to closer cooperation in the future.
Looking back at the history of energy development for a century, it has become a trend, and necessary, to power the world with green energy. RCT Power is sincerely committed to protecting the environment through all its household energy storage systems, industrial and commercial energy storage systems and grid energy storage systems. Reform and innovation are both required to win the green energy race and RCT Power are honored to join hands with TDengine and work together for the cause of green energy.